MoCl_n(OR)_(4_n)-(i-Bu)_2AlOPh 体系催化合成1,2-聚丁二烯的研究

<正> 在前报中,报道了用MoCl_n(OC_8H_17)_(4_a)-(i-Bu)_2AlOPh 催化体系合成1,2-聚丁二烯的工作,发现 MoC_n(OC-8H_17)_(4_n) 在加氢汽油中的溶解性高于MoCl_4~[2],且催化活性也有提高。本文在以前工作基础上,选用不同的OR基团,研究了MoCl_(OR)_(4_n)在加氢汽油中的溶解性及其催化行为与R基的关系,探讨了主、助催化剂用量及配比对聚合活     

WCl4(OR)2Al(i-Bu)3体系合成1,2-聚丁二烯的研究

分析了五种醇与WCl₆在室温下交换反应产物氯含量,表明产物中W:Cl=1:4,故产物可写为WCl₄(OR)₂。以WCl₄(OR)₂-Al(i-Bu)₃为催化体系,在加氢汽油溶剂中可使丁二烯聚合,得到1,2-链节含量在80%,全同立构体在60%以上的聚合物。几种醇中,以n-C₁₀H₂₁OH交换产物的催化活性最高。各种聚合条件的改变,对聚合物微观结构及分子量分布影响不明显。     

CONFIGURATION OF VO(OR)_2Cl-Al(i-Bu)_3 CATALYST SYSTEM AND CHARGE DISTRIBUTION OF VANADIUM CENTRAL ION

According to the caiculation of quantum chemistry it come be deduced that conngurauons or the catalysts VO(OR)_2Cl-Al (i-Bu)_3, for the alternating Copolymerization of butadiene with propene, the highest reactive configuration was A. When the catalyst complex forms the configuration A, the energy of the system was the lowest; the central vanadium atom had relatively high positive charge and whose frontier orbital overlapped easily with the frontier orbital of butadiene to form coordination complex, so it was concluded from the experimental results and calculations that the configuration of the catalyst of relatively high activity was A.     

异戊二烯在Nd(naph)_3-Al(i-Bu)_3-Al_2(C_2H_5)_3Cl_3催化体系作用下聚合动力学

本文研究了异戊二烯在稀土催化剂作用下聚合动力学的一般规律。通过稳态处理及分段聚合证明,体系的活性中心数目基本稳定。聚合转化率低于50％时,聚合速率与单体浓度呈一级关系,同催化剂浓度为1.7级关系。聚合表观活化能为9.0千卡/克分子。聚合物的特性粘数随转化率增加而增大的事实,说明本体系具有某些“活性”聚合的特性。     

WOBr_4催化聚苯乙炔的合成与表征

本文研究了苯乙炔在WOBr_4催化剂作用下的聚合行为,并对催化聚合机理进行了探讨。所得聚合物是可溶可熔的褐红色固体,其最高分子量为1830(M_n)。WOBr_4催化剂具有催化剂用量少(2/100),聚合反应时间短(10秒钟),产物收率高(80％以上)等特点。结构分析结果表明,WOBr_4催化聚苯乙炔具有顺-反式微观结构。     

MoCl4-(i-Bu)2AlOAr体系引发丁二烯聚合的研究

 由MoCl₄为主催化剂,(i-Bu)_3Al与酚类反应的产物(i-Bu)₂AlOAr为助催化剂所组成的催化体系,在加氢汽油中引发丁二烯聚合,研究酚类结构对聚合反应的影响。结果表明,带有推电子基团的酚类,可以提高丁二烯岵,聚合速度,其顺序为双酚A>间甲酚间>β-萘酚>苯酚>对氯酚。测定了丁二烯聚合的表现活化能E_α,催化剂利用率α,活性中心浓度[P*],和活性中心的平均寿期L。     

四价钼催化体系合成高乙烯基聚丁二烯的研究

<正> 五价钼催化体系用于1,2-聚丁二烯的合成已有较多的报道。本工作在以前研究结果的基础上,对四价钼体系催化丁二烯的聚合规律进行了初步研究。 聚合操作在严格的除氧和去水的气氛下进行,聚合产物的分析同前报,除特殊指明者外,聚合条件均为Mo/Bd=2.0×10_-4(摩尔比),50℃,聚合7小时。     

稀土催化体系Nd(napb)_3-AlEt_2Cl-Al(i-Bu)_3对双烯烃聚合的活性

分析了催化剂Nd(naph)_3-AlEt_2Cl-Al(i-Bu)_3三组分反应产物的组成,用动力学方法研究了其催化异戊二烯聚合的活性。催化剂各组分的配比及制备方法对其活性及利用率有显著影响。催化剂的利用率随它使用时浓度的减小而增大,最后达到恒定链终止反应由体系中过量的AlEt_2Cl吸附于活性体而发生。     

STUDY ON SYNTHESIS OF HIGH VINYL POLYBUTADIENE WITH TETRAVALENT MOLYBDENUM CATALYST SYSTEM

In this paper the catalytic behaviour of tetravalent molybdenum catalyst system in polymeriza-tion of butadiene is dealt with. The effects of the variety of apions combined with molybdenumatom, the pattern of the substituent R in (i-Bu)_2AlOR and the polymerization conditions on thebutadiene conversion, the molecular weight and its distribution and the microstructure of the polymeralso are studied. It has been found that the catalyst system is significantly active when anions com-bined with the molybdenum atom are acetoxy (CH_3COO-),or ethoxy (C_2H_5O-). Obviously, thevariety of substituent R in (i-Bu)_2 AlOR has a great influence on the catalytic activity. The catalystsystem is inactive if the R group is--COR' (R'is alkyl or aromatic group) or alkyl, whereas the activityof the catalyst system increases if the R group is phenyl or tolyl. With the rise of polymerizationtemperature the polymer molecular weight decreases, the distribution index of molecular weight in-creases and the content of 1,2-unit in polybutadiene reduces.     

THE POLYMERIZATION OF EPICHLOROHYDRIN WITH Nd(i-oPr)_3-Al(i-Bu)_3 SYSTEM

Epichlorohydrin (ECH) was polymerized with a rare earth catalytic system: Nd (i-OPr)_3-Al (i-Bu)_3. The effects of Al/Nd molar ratio, solvents, the polymerization time and temperature,the aging time and temperature of the catalyst preparation were studied. The results showed thatat a low Al/Nd molar ratio (4) of the Nd(i-OPr)_3-Al(i-Bu)_3 system ECH polymerized at a lowtemperature (248K) with a high conversion. The average molecular weight ofpolyepichlorohydrin (PECH) ranged from 1×10~5 to 3×10~5.     

A new three-dimensional cobalt phosphate: Co5(OH2)4(HPO4)2(PO4)2

A three-dimensional (3D) cobalt phosphate: Co₅(OH₂)₄(HPO₄)₂(PO₄)₂ (1), has been synthesized by hydrothermal reaction and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic techniques. The title compound is a template free cobalt phosphate. Compound 1 exhibits a complex net architecture based on edge- and corner-sharing of CoO₆ and PO₄ polyhedra. The magnetic susceptibility measurements indicated that the title compound obeys Curie-Weiss behavior down to a temperature of 17 K at which an antiferromagnetic phase transition occurs.     

Ba3 (VO4)2-K2 Ba(MoO4)2 and Pb3 (VO4)2-K2 Pb(MoO4)2 systems

Phase equilibria in the Ba₃(VO₄)₂-K₂Ba(MoO₄)₂ and Pb3(VO₄)₂-K₂Pb(MoO₄)₂ systems have been investigated. In the first system, a continuous series of substitutional solid solutions with the palmierite structure is formed, and in the second one, the polymorphic transition in lead orthovanadate at 100°C restricts the extent of the palmierite-type solid solution to 10–100 mol % K₂Pb(MoO₄)₂. Original Russian Text ? V.D. Zhuravlev, Yu.A. Velikodnyi, A.S. Vinogradova-Zhabrova, A.P. Tyutyunnik, V.G. Zubkov, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 10, pp. 1746–1748.     

AQUEOUS PHASE SYNTHESIS OF(RC_5H_4)_2Ti(O_2CC_6H_4X)_2

Nine complexes(RC_5H_4)_2Ti(O_2CC_6H_4X)_2(R=H,CH_3;X=H,o-Cl,o-OH,o-NH_2,o-NHPh)have been conveniently prepared by the reaction of(RC_5H_4)_2TiCl_2 with 2 equiv.sodium salts of corresponding carboxylic acidin aqueous solution containing acetylacetone.The carboxylate ligands inthe complexes coordinate to titanium atom in monodentate mode.     

A novel three-dimensional malonate-bridged complex {[Cu4(4,4′- bpy)8(mal)2(H2O)4](ClO4)2(H2O)4(CH3OH)2}n

A novel malonate-bridged copper (II) compound of formula {[Cu₄(4,4′-bpy)₈(mal)₂(H₂O)₄](ClO₄)₂(H₂O)₄(CH₃OH)₂}_n (4,4′-bpy = 4,4′-bipyridine; mal = malonate dianion) has been prepared and structurally characterized by X-ray crystallography. This compound exhibits a novel three-dimensional network being composed of Cu-4,4′-bipyridine layers which are pillared by malonate bridge ligands. The copper(II) ions has two different coordination environment.     

Crystal structures of phosphomolybdyl salts: Pb(MoO2)2(PO4)2 and Ba(MoO2)2(PO4)2

Crystal structures of Pb(MoO₂)₂(PO₄)₂ and Ba(MoO₂)₂(PO₄)₂ were determined. Both compounds contain the molybdyl group MoO₂. The monoclinic unit-cell parameters are a = 6.353(7), b = 12.289(4), c = 11.800 Å, β = 92°56(6), and Z = 4 for the lead salt and a = 6.383(8), b = 7.142(7), c = 9.953(8) Å, β = 95°46(8), and Z = 2 for the barium salt. $\text{P2}{}_1\text{c}$ is the common space group. The R values are respectively R = 0.027 and R = 0.031 for 1964 and 1714 independent reflections. The frameworks built up by a three-dimensional network of monophosphate PO₄ and molybdyl MoO₂ groups are similar, characterized mainly by corner-sharing PO₄ and MoO₆ polyhedra. Two oxygen atoms of each MoO₆ group are bonded to the molybdenum atom only as in other molybdyl salts.     

COPOLYMERIZATION OF ETHYLENE WITH 1-OCTENE USING Et(Ind)2ZrCl2/MAO CATALYST

Copolymerization of ethylene/1-octene was carried out in toluene withvarious concentrations of comonomer in the feed using Et(Ind)_2ZrCl_2/MAO (methyl alu-minoxane) as catalyst. It was found that with the increase of 1-octene concentration in thefeed the content of 1-octene in the copolymer increases, while the density, melting point,crystallinity and intrinsic viscosity of copolymer decrease. A copolymer with very lowdensity, containing 11.5 mol% of 1-octene (VLLDPE) can be produced with this catalystsystem. The effect of temperature and zirconium aluminum mole ratio of the catalyst onthe copolymerization was also investigated. The results of ~(13)C NMR determination of thecopolymer showed that the 1-octene units in the copolymer are principally isolated.     

Phase transformation in Y2[Pt(CN)4]3-21H2O

Y₂[Pt(CN)₄]₃21H₂O (YCP) crystallizes in a columnar structure type with a mean in-chain PtPt distance of R = 3.18 A. At T_c = (218.5 ± 1) K YCP undergoes a first order phase transformation which is investigated spectroscopically (polarized emission) and thermodynamically (specific heat and differential thermal analysis). It is possible to record polarized emission spectra from the high temperature phase (phase I) T >T_c, the low temperature phase (phase II) T <T_c, and the supercooled phase I. From the spectroscopic data we deduce a PtPt distance reduction (at T_c) of ΔR = (?0.04 ± 0.005) A. The enthalpy of the transition from phase I to phase II is about +1500 J/mole.     

在稀土体系催化下的丁二烯聚合动力学

本文应用键谷勤聚合动力学公式进行动力学研究。求出了活性中心数目,有关的动力学常数和聚合速度方程(R_p=k_p[C~*][M])并着重研究了聚合物活性链性质。 在链引发阶段,发现20℃和50℃聚合,属于迅速引发类型,在0℃时则是缓慢引发类型。聚合过程中,存在明显的链转移反应。Al(i-C_4H_9)_3是主要的链转移剂。在50℃聚合时,有活性中心失活现象发生,并表明其为双基终止。     

[COH(NH2)2]2[Cu(pic)2(ClO4)2]的合成与晶体结构

The title compound was synthesized by reaction of Cu(ClO₄)₂， picolinic acid and carbamide in C₂H₅OH/CH₃CN solution， and characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system， space group Pbca with a=14.0481(8)， b=9.0130(5)， c=18.626(1)?， V=2358.3(2)?³， Z=4， D_x=1.771g·cm^-3， μ=1.235mm^-1 and F(000)=1276. The final R factor is 0.0440 for 1434 observed reflections. The X-ray analysis revealed that the copper(Ⅱ) atom is coordinated by two picolinic ligands in the equatorial plane， while the two oxygen atoms of perchlorate occupy the axial positions of octahedron with lengthened Cu-O distances， resulting in a 4+2 elongated octahedral environment. In the compound， there also exist two protonated carbamide cations for charge balance. CCDC： 195354.     

COPOLYMERIZATION OF BUTADIENE AND ISOPRENE CATALYZED BY V(acac)_3-Al(i-Bu)_2Cl-Al_2Et_3Cl_3 CATALYST AND CHARACTERIZATION OF THE PRODUCTS

Copolymerization of butadiene and isoprene catalyzed by the catalyst system V(acac)_3-Al(i-Bu)_2Cl-Al_2Et_3Cl_3 has been studied. Composition, microstructure, crystallinity and melting point of the copolymer obtained were determined by PGC, IR, X-ray diffraction and DSC methods respectively. The results revealed that the product was a copolymer and not a blend. The butadiene units presented in the copolymer were of trans-1,4-configuration, while the isoprene units were of both trans-1,4-and 3,4-forms. The melting point and crystallinity of the copolymer decrcascd with increase of molar ratio of isoprene to hutadiene.